High tension stop motion for tufting machines



HIGH TENSION STOP MOTION FOR TUFTING MACHINES Filed Aug. 19, 1965 2 Sheets-Sheet 1 BIA E1.

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HIGH TENSION STOP MOTION FOR TUFTING MACHINES Filed Aug. 19, 1965 2 Sheets-Sheet 2 INVENTOR DAVID G. BURNELL United States Patent HIGH TENSION STOP MOTION FOR TUFTING MAGHINES David G. Bumell, Clayton, Ga., assignor. to James Lees- This invention relates to tufting machinery for produc-.

ing tufted pile fabrics of the type used as floor coverings. Moreparticularly, the invention pertains to the, use of a device for detecting tension in a running yarn end which exceeds a predetermined value in the area between the creel and the needles of a tufting machine,

Machines for producing tufted pile fabric customarily employ anywhere from one to fifteen hundred needles mounted for vertical reciprocation in a needle bar. These needles insert pile yarns through a moving backing sheet in such a way that the yarns carried by the needles may be engaged by oscillating loopers underneath the backing sheet to produce cut and/or uncut pile projections. In certain instances it is desirable to utilize what is known as a pattern attachment, these may take one of several forms, but a well-known type of such pattern attachment employs a plurality of pairs of rollers which are selectively driven at different speeds in accordance with a prograrnrning device. The yarn ends fed from a creel are carried over and under selected pairs of rollers so that the rate. of feed and/ or the tension introduced into these yarn ends by the patternattachment may be utilized to control the pile height of the various ends. This produces what is known as a patterned or sculptured eifect in thepile of the fabric.

In running certain types of yarn and particularly a bulked continuous filament yarn such as nylon, it has been foundthat especial ,care must be given to the tension developed in the yarn between the tufting machine and the creel. For large equipment such as a fifteen foot tufting machine the yarn ends are carried from the creel to the pattern attachment through a series of tubes which may be anywhere from fifteen to thirty or forty feet in length. Sometimes these tubes collect lint or other material with which the yarn may be finished to such an extent that the friction of the yarns, in the tubes reaches such a degree that the yarn ends break. A more prevalent condition caused by excessive tension in one or two yarn ends produces a phenomenon known as tension streaks. This simply means that all of the pile projections formed by a particular yarn end are lower than the pattern requires with a result that when the fabric is placed on the floor this rowof low pile projections shows ,up as a discernible streak thus causinga defect.- Due to the fact that some synthetic fibers and especially nylon are very tough and have a relatively high breaking strength, abroken end causing the operator to stop themachine does not ordinarily occur until after the above described streaky condition has continued for some time. The tuftiug machine opera tor cannot see the fabric being tufted without walking around the endof the machine to the back at frequent intervals. This is not always practical. Therefore, a tension streak is not always easy to detect during the actual tufting of the fabric so that the tufting machine attendant cannot make a correction until many yards of fabric have been produced and sometimes this is not even noticeable until the fabric is finally unrolled on the inspection floor. A still further complication arises out of the fact that bulked yarn inherently has more stretch and ability to contract after stretching than does wool for example. This ability of nylon to elongate without rupture but to recover its original length after a substantial lapse of time is well known and is described in U.S Patent 2,407,634 to Richard C. du Pont;

The above factors indicate the importance offproviding an extremely sensitive tension detector in a tufting machine which has the ability to detect tensions in excessof those normally required to pull the various yarn ends throughthe tubes under conditionsin which the, internal" friction of the tubes varies over wide ranges and thus to avoid excessivetension causing tension streaks or even yarn breakage. Obviously such a device cannot be located between the pattern attachment and the needles sincethe pattern attachment itself causes wide tension variations which result in a controlled location ofthe high and low pile as distinguished from a defect due to a series of'low pile projections in one or two ends running lengthwise in the fabric.

The present invention therefore has for its primary object the provision of a sensitive tension detector positioned' on a tufting machine immediately inadvance of thepattern attachment and between the pattern attachment and the creel tubes.

A further object of theinvention is to provide a tension streak detector in a tufting machine which can be. ac-

curately adjusted to -detect tensions on the order of a few.

grams in excess of a predetermined value.

A further object of the invention is to, provide a sensitive tension detector for tufting machines orthe like which can be operated up to a predetermined value withwide fluctuations but which when the machine is operatingwill knock oifthe machine after the predetermined value has been exceeded for a timed interval.

Further objects will be apparent from the specification and drawings in which FIG. 1 is a transverse schematic section through a multi-needle tufting machine and asix'roll pattern attachment, showing the tension streakdetector innermal operation,

FIG. 2 is an enlarged fragmentary detail showing a top:

view of one; segment of the tension detector assembly,

FIG. 3 is a sectional view as seen at 3 -3 of FIG. 2,-

FIG. 4 is a view similar to FIG: 3 show-ing'the tension' detector pivoted to the knockofit position,

FIG. 5 is a longitudinal section; of the micro-switch The invention comprises essentially the pr0vision ofaseries of journaled yarn guide plates positionedbetween the pattern attachment and the creel tubes and-having thecenter line of the journal substantially midway between two yarn guides so that static tension is insufiicient to-pivot the tension guide bar but excessive running or operatingtensi-on in any one of the yarn ends will pivot atleast one of the tension guides to a position in which a circuit is opened to a relay which in turnshuts down the tu'fting machine.-

Referring more particularly to the drawings, a conventional broad or yardage tufting machine comprises a bed '20 over which a backing fabric-or sheet F is fed from a pin feed roll 21 by means of a pin feed take-up roll 22. Rolls 23 and 24 cooperate with rolls 21 and 22 to maintain fabric contact therewith. As the fabric F passes over the throat or bed 20 of the tufting machine a series of pile yarns Y are carried through the fabric by means of needles 25, 25 mounted in needle bar 26. The needle bar 26 is journaled in sleeves 27 and is reciprocated vertically by means of a crankshaft 28 having eccentric driven cranks 29 and connecting rods 30. The latter elements are mounted in the upper tufting machine housing 35 which is supported by pedestal 36 and provided with a stationary yarn guide 37 as well as a presser foot assembly 38. The needle bar 26 also carries the conventional jerker bar 39 and a series of loopers 40, 40 mounted on looper rocksha'ft 41 reciprocate through a suitable arc to engage the yarn in the needles. All of the above structure is conventional and needs no further detailed description. The pattern attachment shown in FIG. 1 is intended to exemplify any type of such attachment which controls the yarn feed. In a six roll (six pairs) pattern attachment, one sixth of the yarn ends is carried over the top pair of feed rolls 45 and additional sixths of the yarn ends are carried over the other pairs 46, 47, 48, 49, and 50. Before passing over each pair of rolls the yarn ends Y are carried through stationary yarn guides 55, 56, 57, 58, 59, and 60.

Immediately above the top yarn guide 55 I mount a cross-shaft 61 which carries a series of pivoting arms 62, 62 (FIG. 2). The location of shaft 61 is substantially between the upper stationary guide 55 and a stationary yarn guide 63 positioned just below the outlets of the various creel tubes 64, 64. The yarns are drawn from a creel 615 through the creel tubes 64 by feed rolls 45-50 all in accordance with well known practice. Each of the pivoting tension detectors comprises a series of angles 66, each angle being approximately 14 to 16 inches long and provided with a double row of treated yarn apertures 67, 67 through which the yarns Y are fed from the upper guide 65. The bars 62, 62 are mounted on bearings 70, 70 which freely pivot on shaft 61. Spacing collars 71, 71 are anchored to shaft 61 by means of set screws 72, 72 and prevent axial movement of the bearings 70 on shaft 61. Counter Weights 73 and 74 are slidable on rods 75 and 76 respectively which rods are mounted in the bearings 70 and retained therein by means of lock nuts 77. Counter clockwise pivoting of each detector assembly is prevented by means of a stop rod 78 against which the rods 75 and 76 strike to prevent undesired rotating beyond a substantially horizontal position as shown in FIG. 3. Mercury switch 80 is retained in clip 81 secured to one of each pair of bearings 70 shown in FIGS. 3 and 4. When the tension in any one of the running yarn ends Y exceeds a value sufficient to cause tipping of the detector, the arms pivot in a clockwise direction as shown in FIG. 4. This opens the contact between elements 82 and 83 (FIG. 6) in the switch proper thereby opening a circuit to stop the machine.

Referring now more particularly to FIG. 7 each of the mercury switches 80, 80 is connected in series so that if any one of the switches across the machine is opened, the circuit to relay R1 from main lines 85 and 86 is opened thus de-energizing relay R1 which in turn opens normally closed contacts Rla to de-energize relay R2 thus stopping the machine motor 87. Relay R1 is a time delay relay normally set at approximately five seconds so that if the operator or the creel attendant inadvertently applies excess tension to the tufting machine it will not be stopped unless such excess tension continues. In this way momentary increases in tension which would not cause a long tension streak are prevented from shutting off the tufting machine. The time delay feature is also important when starting the machine up since the initial friction on the angles 66, 66 due to movement of the yarn ends will cause the detectors to pivot, but as soon as normal operating speed is reached, the tension detectors all resume their normal substantially horizontal positions shown in FIGURE 3.

It will thus be understood that I have produced an extremely sensitive and satisfactory tension streak detector which may be effectively used to prevent undesired tension streaks in a tufted fabric. The device is very effective in eliminating a most vexing problem incident to the high speed tufting of bulked continuous filament synthetic yarn. Also it is to be noted that if tension is applied to any one of the yarn ends when the machine is not in operation, the tension detector will not pivot due to the relative location of shaft 61 and yarn guides 55 and 65. This feature is also of importance in the event it may be desired to raise or lower the overall normal operating tension for a particular type of yarn or fabric being produced.

Having thus described my invention, I claim:

1. In pile fabric tufting apparatus having a creel, a plurality of needles reciprocable to penetrate a backing material fed to the needles, a series of yarn guides for directing yarn ends to said needles, a motor for operating said needles, and means including creel tubes for feeding yarn ends from the creel to the needles, the improvement which comprises first stationary yarn guides mounted adjacent the discharge ends of the creel tubes, second stationary yarn guides mounted in spaced relation to said first yarn guides, yarn contacting elements journaled between said two stationary yarn guides, said elements having yarn contacting surfaces offset from the straight line path between said stationary yarn guides to normally engage and deflect the travelling yarn ends from said straight line path, pivot means for mounting said elements, an electrical switch secured thereto and directly operable by the pivoting of each of said elements, electrical connections between said switch and the motor whereby the circuit to the motor is opened when the yarn contacting means pivots to a predetermined position to thereby shut off said motor when excessive tension is present in a feeding yarn, and time delay means to prevent opening of the circuit to the motor until a predetermined interval has elapsed after one of the elements has pivoted due to excessive tension in a feeding yarn.

2. Apparatus in accordance with claim 1 in which the yarn contacting elements have first andsecond portions, said first portions having yarn contacting surfaces and said second portions having electrical switch contact means thereon.

8. Apparatus in accordance with claim 2 having a counterweight on the second portions and a stop for preventing reverse pivoting of the elements.

References Cited by the Examiner UNITED STATES PATENTS 1,877,647 9/1932 Crawford 66161 2,448,615 9/1948 Mosley 307-l41.4 X 2,569,442 10/ 1951 Anderson 200-61.8 X 2,791,820 5/1957 Spencer 66163 2,862,465 12/ 1958 Card 112-79.6 3,094,855 6/ 196'3 Vossen 112-79 X 3,103,755 9/1963 Hajos 38143 JORDAN FRANKLIN, Primary Examiner. 

1. IN PILE FABRIC TUFTING APPARATUS HAVING A CREEL, A PLURALITY OF NEEDLES RECIPROCABLE TO PENETRATE A BACKING MATERIAL FED TO THE NEEDLES, A SERIES OF YARN GUIDES FOR DIRECTING YARN ENDS TO SAID NEEDLES, A MOTOR FOR OPERATING SAID NEEDLES, AND MEANS INCLUDING CREEL TUBES FOR FEEDING YARN ENDS FROM THE CREEL TO THE NEEDLES, THE IMPROVEMENT WHICH COMPRISES FIRST STATIONARY YARN GUIDES MOUNTED ADJACENT THE DISCHARGE ENDS OF THE CREEL TUBES, SECOND STATIONARY YARN GUIDES MOUNTED IN SPACED RELATION TO SAID FIRST YARN GUIDES, YARN CONTACTING ELEMENTS JOURNALED BETWEEN SAID TWO STATIONARY YARN GUIDES, SAID ELEMENTS HAVING YARN CONTACTING SURFACES OFFSET FROM THE STRAIGHT LINE PATH BETWEEN SAID STATIONARY YARN GUIDES TO NORMALLY ENGAGE AND DEFLECT THE TRAVELLING YARN ENDS FROM SAID STRAIGHT LINE PATH, PIVOT MEANS FOR MOUNTING SAID ELEMENTS, AN ELECTRICAL SWITCH SECURED THERETO AND DIRECTLY OPERABLE BY THE PIVOTING OF EACH OF SAID ELEMENTS, ELECTRICAL CONNECTIONS BETWEEN SAID SWITCH AND THE MOTOR WHEREBY THE CIRCUIT TO THE MOTOR IS OPENED WHEN THE YARN 